Mutually induced filters

ABSTRACT

A mutually induced filter for filtering radio frequency (RF) power from signals supplied to a load is described. The mutually induced filter includes a first portion connected to a first load element of the load for filtering RF power from one of the signals supplied to the first load element. The load is associated with a pedestal of a plasma chamber. The mutually induced filter further includes a second portion connected to a second load element of the load for filtering RF power from another one of the signals supplied to the second load element. The first and second portions are twisted with each other to be mutually coupled with each other to further facilitate a coupling of a resonant frequency associated with the first portion to the second portion.

FIELD

The present embodiments relate to mutually induced filters used in aplasma processing system.

BACKGROUND

Generally, process reactors are used to process operations upon wafers,e.g., silicon wafers. These wafers are typically processed numeroustimes in various reactors in order to form integrated circuits thereon.Some of these process operations involve, for instance, depositingmaterials over select surfaces or layers of a wafer. One such reactor isa plasma enhanced chemical vapor deposition (PECVD) reactor.

For example, a PECVD reactor may be used to deposit insulation filmssuch as silicon oxide (SiO), silicon nitride (SiN), silicon carbide(SiC), silicon oxide carbide (SiOC), and others. Conductor films mayalso be deposited using PECVD reactors. Such material films, to name afew examples, may include tungsten silicide (WSi), titanium nitride(TiN), aluminum (Al) alloy, etc. Depending on the type of film beingdeposited, specific reaction gases are brought into the PECVD reactorwhile radio frequency (RF) power is supplied to produce a plasma thatenables the deposition.

During the deposition process, systems and circuitry are used to setand/or monitor settings and operational parameters. One exampleparameter is temperature, e.g., which is controlled by heaters embeddedin a substrate support of a reactor. In some cases, the circuitry usedto set, control and/or monitor parameters can become complex andextensive. In addition, some systems require rotation of the wafer whileprocessing, which further requires additional circuitry and control.Conventionally, as reactor systems become more complex, more circuitryis added to enable the settings, control and/or monitoring.Unfortunately, as reactor system increase in complexity, so does thesize and cost of such systems.

It is in this context that embodiments described in the presentdisclosure arise.

SUMMARY

Embodiments of the disclosure provide apparatus, methods and computerprograms for fabricating and using a mutually induced filter used in aplasma processing system. It should be appreciated that the presentembodiments can be implemented in numerous ways, e.g., a process, anapparatus, a system, a device, or a method on a computer-readablemedium. Several embodiments are described below.

In one embodiment, a mutually induced filter is provided. The mutuallyinduced filter filters radio frequency (RF) power that may interferewith a signal, e.g., an alternating current (AC) signal, a directcurrent (DC) signal, etc., that is being supplied to a load or that isbeing received from a load. The interfering RF power is generated fromRF power that is supplied from one or more RF generators to a pedestalwithin a plasma chamber. The mutually induced filter is fabricated bytwisting one or more wires to form a combination of wires and thenwinding the combination into a plurality of turns to form multipleinductors. Moreover, a capacitor is connected to one of the inductors. Aresonant frequency of a combination of the capacitor and the one of theinductors is transferred from the one of the inductors to remaining ofthe inductors of the mutually induced filter so that the mutuallyinduced filter has the resonant frequency. Any signals passing throughthe mutually induced filter are filtered at the resonant frequency. Inan embodiment, another capacitor is connected to another one of theinductors and another resonant frequency of a combination of the othercapacitor and the other one of the inductors is transferred from theother one of the inductors to remaining inductors of the mutuallyinduced filter to couple the other resonant frequency to the mutuallyinduced filter. Any signals passing through the mutually induced filterare filtered at both the resonant frequencies.

In one embodiment, a mutually induced filter for filtering radiofrequency (RF) power from signals supplied to a load is described. Themutually induced filter includes a first portion connected to a firstload element of the load for filtering RF power from one of the signalssupplied to the first load element. The load is associated with apedestal of a plasma chamber. The mutually induced filter furtherincludes a second portion connected to a second load element of the loadfor filtering RF power from another one of the signals supplied to thesecond load element. The first and second portions are twisted with eachother to be mutually coupled with each other to further facilitate acoupling of a resonant frequency associated with the first portion tothe second portion.

In an embodiment, a mutually induced filter for filtering RF power fromsignals received from a load is described. The mutually induced filterincludes a first portion connected to a first load element of the loadfor filtering RF power from one of the signals received from the firstload element. The mutually induced filter includes a second portion ofthe mutually induced filter connected to a second load element of theload for filtering RF power from another one of the signals receivedfrom the second load element. The first and second portions are twistedwith each other to be mutually coupled with each other to furtherfacilitate a coupling of a resonant frequency associated with the firstportion to the second portion.

In one embodiment, a mutually induced filter for filtering RF power fromsignals associated with a plurality of loads is described. The mutuallyinduced filter includes a first portion connected to a first loadelement of a first one of the loads for filtering RF power from one ofthe signals supplied to the first load element. The first load isassociated with a pedestal of a plasma chamber. The mutually inducedfilter includes a second portion connected to a second load element ofthe first load for filtering RF power from another one of the signalssupplied to the second load element. The mutually induced filter alsoincludes a third portion connected to a first load element of a secondone of the loads for filtering RF power from one of the signals receivedfrom the first load element of the second load. The second load isassociated with the pedestal of the plasma chamber. The mutually inducedfilter includes a fourth portion of connected to a second load elementof the second load for filtering RF power from another one of thesignals received from the second load element of the second load. Thefirst, second, third, and fourth portions are twisted and wound witheach other to be mutually coupled with each other to further facilitatea coupling of a resonant frequency associated with the first portion tothe second, third, and fourth portions and a resonant frequencyassociated with the fourth portion to the first, second, and thirdportions.

Some advantages of the embodiments described herein include arranging afirst portion of a mutually induced filter and a second portion of themutually induced filter to mutually couple the portions with each other.A current in the first portion creates an induced electromotive force inthe second portion. The electromotive force generates a current withinthe second portion to mutually couple the first and second portions.Moreover, as a result of the mutual coupling, a resonant frequencyassociated with the first portion is coupled to the second portion toprovide a uniformity in the resonant frequency across both the first andsecond portions for filtering RF power from a signal. The uniformity inthe resonant frequency provides uniformity in processing a substrate,etc.

Also, as another advantage, a current in the second portion creates aninduced electromotive force in the first portion. The inducedelectromotive force generates a current passing through the firstportion to mutually couple the second portion to the first portion.Moreover, as a result of the mutual coupling, a resonant frequencyassociated with the second portion is coupled to the first portion toprovide a uniform resonant frequency across both first and secondportions for filtering RF power from the a signal passing through thefirst portion provide uniformity in processing a substrate.

Moreover, a high amount of mutual coupling in the first and secondportions results in a high level of mutual inductance, and the highlevel of mutual inductance results in achieving improved common moderejection.

Further advantages of the embodiments described herein include that onechannel to which a capacitor is coupled is tuned for each frequencyband. Mutual coupling between inductors of the mutually induced filterfacilitates a coupling of the tuned frequency of the mutually inducedfilter to other channels of the mutually induced filter. This saveslabor time and costs associated with tuning multiple capacitors ofpreviously used filters, which are further described below.

Additional advantages of the embodiments described herein include usinga lower number of filters to filter RF power from signals associatedwith heaters, thermocouples, and a motor. Previously, for example, eachchannel of a filter included two filters, one for filtering RF powerfrom at a high frequency and one for filtering RF power from at a lowfrequency. The two filters were coupled in series. For two heaterelements or two thermocouples or a motor, 8 such filters were used. Fortwo heater elements, two thermocouples, and one motor, 24 such filterswere used. The use of 24 filters increases sizes of filter boxes inwhich the 24 filters are fitted. In case of four stations, 96 suchfilters were used. Comparatively, the embodiments described herein usethree mutually induced filters per station, one for two heater elements,one for two thermocouples, and one for a motor. Each mutually inducedfilter has one or two resonant frequencies. In case of four stations, 12mutually induced filters are used, instead of 96 filters usedpreviously. The lower number of mutually induced filters reduces time,cost, and space associated with the 96 filters. For example, eachmutually induced filter is fitted into a smaller size package comparedto the 8 previously used filters. As another example, it takes less timeto assemble a mutually induced filter than taken to assemble the 8previously used filters. The 8 previously used filters include 8capacitors and 8 inductors, which are greater than 2 capacitors and 6inductors used in the mutually induced filter. The higher number ofcapacitors and inductors in the previously used filters increases anamount of time to assemble the previously used filters compared to timetaken to assemble the mutually induced filter.

Also, mutual inductance results in a coupling of a resonant frequencyacross the mutually induced filter, and the uniform resonant frequencyincreases chances of channel-to-channel matching, station-to-stationmatching, and tool-to-tool matching.

Other aspects will become apparent from the following detaileddescription, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments may best be understood by reference to the followingdescription taken in conjunction with the accompanying drawings.

FIG. 1 illustrates a substrate processing system, which is used toprocess a wafer, in accordance with some embodiments described in thepresent disclosure.

FIG. 2 illustrates a top view of a multi-station processing tool, wherefour processing stations are provided, in accordance with variousembodiments described in the present disclosure.

FIG. 3 shows a schematic view of a multi-station processing tool with aninbound load lock and an outbound load lock, in accordance with variousembodiments described in the present disclosure.

FIG. 4A is a diagram of a plasma processing system to illustrate use ofmutually induced filters with various components of the plasmaprocessing system, in accordance with some embodiments described in thepresent disclosure.

FIG. 4B is a circuit diagram of any one of the mutually induced filtersof FIG. 4A, in accordance with various embodiments described in thepresent disclosure.

FIG. 4C is a diagram of any one of the mutually induced filters of FIG.4A in which the six wires are twisted and wound together to form sixinductors, in accordance with several embodiments described in thepresent disclosure.

FIG. 5A is a diagram a mutually induced filter coupled to heaterresistors of the substrate processing system of FIG. 1, in accordancewith some embodiments described in the present disclosure.

FIG. 5B is a diagram of a mutually induced filter coupled tothermocouples used within the substrate processing system of FIG. 1, inaccordance with some embodiments described in the present disclosure.

FIG. 5C is a diagram of a mutually induced filter coupled to a motor anda power supply, in accordance with various embodiments described in thepresent disclosure.

FIG. 5D shows a circuit diagram of the mutually induced filter coupledto the resistors, a circuit diagram of the mutually induced filtercoupled to the thermocouples, and a circuit diagram of the mutuallyinduced filter coupled to the motor, in accordance with severalembodiments described in the present disclosure.

FIG. 6 is a diagram of a filter, which includes a first portion and asecond portion, to illustrate mutual coupling between the portions, inaccordance with several embodiments described in the present disclosure.

FIG. 7 is a diagram of an embodiment of a mutually induced filter toillustrate that mutual coupling is achieved between a first portion ofthe mutually induced filter that filters RF power from signalstransferred between heater elements and power supplies and a secondportion of the mutually induced filter that filters RF power fromsignals transferred between the motor and an AC power source, inaccordance with some embodiments described in the present disclosure.

FIG. 8A is a graph to illustrate that resonant frequencies of mutuallycoupled portions of a mutually induced filter are the same orsubstantially the same, in accordance with several embodiments describedin the present disclosure.

FIG. 8B is a circuit diagram of the mutually induced filter of FIG. 8A,in accordance with several embodiments described in the presentdisclosure.

FIG. 9 is a diagram illustrating a cross-section of a filter, inaccordance with some embodiments described in the present disclosure.

FIG. 10A is a diagram of a graph for illustrating similar attenuation bya dual frequency mutually induced filter and exhibition of similarresonant frequencies by components of the dual frequency induced filter,in accordance with various embodiments described in the presentdisclosure.

FIG. 10B-1 illustrates a prototype of a dual frequency mutually inducedfilter that includes the components of FIG. 10A, in accordance withvarious embodiments described in the present disclosure.

FIG. 10B-2 is a circuit diagram of the dual band mutually induced filterof FIG. 10A, in accordance with various embodiments described in thepresent disclosure.

FIG. 11A shows a graph to illustrate an attenuation associated with achannel of the dual band mutually induced filter, in accordance withsome embodiments described in the present disclosure.

FIG. 11B shows a graph to illustrate an attenuation associated withanother channel of the dual band mutually induced filter of FIG. 11A, inaccordance with some embodiments described in the present disclosure.

FIG. 11C shows a graph to illustrate an attenuation associated with yetanother channel of the dual band mutually induced filter of FIG. 11A, inaccordance with some embodiments described in the present disclosure.

FIG. 11D shows a graph to illustrate an attenuation associated withanother channel of the dual band mutually induced filter of FIG. 11A, inaccordance with some embodiments described in the present disclosure.

FIG. 12 is a diagram to illustrate twisting and winding of fourinductors during fabrication of a mutually induced filter, in accordancewith some embodiments described in the present disclosure.

DETAILED DESCRIPTION

The following embodiments describe systems and methods for fabricatingand using a mutually induced filter to achieve one or more resonantfrequencies. It will be apparent that the present embodiments may bepracticed without some or all of these specific details. In otherinstances, well known process operations have not been described indetail in order not to unnecessarily obscure the present embodiments.

Deposition of films is preferably implemented in a plasma enhancedchemical vapor deposition (PECVD) system. The PECVD system may take manydifferent forms. The PECVD system includes one or more chambers or“reactors” (sometimes including multiple stations) that house one ormore wafers and are suitable for wafer processing. Each chamber mayhouse one or more wafers for processing. The one or more chambersmaintain the wafer in a defined position or positions (with or withoutmotion within that position, e.g. rotation, vibration, or otheragitation). A wafer undergoing deposition may be transferred from onestation to another within a reactor chamber during the process. Ofcourse, the film deposition may occur entirely at a single station orany fraction of the film may be deposited at any number of stations.

While in process, each wafer is held in place by a pedestal, e.g., awafer chuck, etc., and/or other wafer holding apparatus. For certainoperations, the apparatus may include a heater such as a heating plateto heat the wafer, a set of thermocouples to measure temperature duringprocessing the wafer, and a motor to rotate the pedestal during theprocessing of the wafer.

A mutually induced filter is used to filter radio frequency (RF) powerfrom a signal, e.g, a direct current (DC) signal, an alternating current(AC) signal, etc., that is being supplied to or received from a load.Examples of the load include the heater, the thermocouples, and themotor. The mutually induced filter is fabricated to achieve mutualinductance or mutual coupling between a first portion of the mutuallyinduced filter and a second portion of the mutually induced filter. Thephenomena of mutually induced filtering is not one associated with atransformer. For example, in a transformer, a mutual inductance isgenerated in a secondary coil of the transformer when a current isapplied to a primary coil of the transformer. The current is applied tothe primary coil when an active AC source, e.g., a voltage AC source,etc., is connected to the primary coil. A change in the current in theprimary coil produces an electromotive force, e.g., a voltage, etc., inthe secondary coil. Comparatively, in the mutually induced filter,described in detail further below, use of passive components, e.g.,inductors, capacitors, etc., within the first portion of the mutuallyinduced filter results in a transfer of one or more resonant frequenciesfrom the first portion to the second portion. A transfer of a signalbetween the passive components within the first portion of the mutuallyinduced filter creates an electromagnetic field. The electromagneticfield induces an electromotive force within the second portion of themutually induced filter to mutually couple inductive components of thefirst and second portions. There is no direct signal being applied tothe first portion such as from an AC power source, etc. The mutualcoupling between the inductive components of the mutually induced filterfacilitates achieving a resonant frequency associated with a combinationof a capacitive component and an inductive component of the firstportion of the filter so that the mutually induced filter has theresonant frequency.

In one embodiment in which a capacitive component is used within thesecond portion of a mutually induced filter in addition to thecapacitive component within the first portion, mutual coupling betweenthe first and second portions of the mutually induced filter facilitatesachieving resonant frequencies associated with combinations ofcapacitive component and inductive components of the mutually inducedfilter.

FIG. 1 illustrates a substrate processing system 100, which is used toprocess a wafer 101. The system includes a chamber 102 having a lowerchamber portion 102 b and an upper chamber portion 102 a. A centercolumn is configured to support a pedestal 140, which in one embodimentis a powered electrode. The pedestal 140 is electrically coupled to aradio frequency (RF) power supply 104 via a match network 106. The powersupply is controlled by a control module 110, e.g., a controller, etc.,which is further described below. The control module 110 operates thesubstrate processing system 100 by executing process input and control108. The process input and control 108 may include process recipes, suchas power levels, timing parameters, process gasses, mechanical movementof the wafer 101, etc., so as to deposit or form films over the wafer101.

The center column is also shown to include lift pins 120, which arecontrolled by lift pin control 122. The lift pins 120 are used to raisethe wafer 101 from the pedestal 140 to allow an end-effector to pick thewafer and to lower the wafer 101 after being placed by the end-effector.The substrate processing system 100 further includes a gas supplymanifold 112 that is connected to process gases 114, e.g., gas chemistrysupplies from a facility. Depending on the processing being performed,the control module 110 controls the delivery of process gases 114 viathe gas supply manifold 112. The chosen gases are then flown into ashower head 150 and distributed in a space volume defined between theshowerhead 150 face that faces that wafer 101 and the wafer 101 restingover the pedestal 140.

Further, the gases may be premixed or not. Appropriate valving and massflow control mechanisms may be employed to ensure that the correct gasesare delivered during the deposition and plasma treatment phases of theprocess. Process gases exit chamber via an outlet. A vacuum pump (e.g.,a one or two stage mechanical dry pump and/or a turbomolecular pump)draws process gases out and maintains a suitably low pressure within thereactor by a close loop controlled flow restriction device, such as athrottle valve or a pendulum valve.

Also shown is a carrier ring 200 that encircles an outer region of thepedestal 140. The carrier ring 200 is configured to sit over a carrierring support region that is a step down from a wafer support region inthe center of the pedestal 140. The carrier ring includes an outer edgeside of its disk structure, e.g., outer radius, and a wafer edge side ofits disk structure, e.g., inner radius, that is closest to where thewafer 101 sits. The wafer edge side of the carrier ring includes aplurality of contact support structures which are configured to lift thewafer 101 when the carrier ring 200 is lifted by spider forks 180. Thecarrier ring 200 is therefore lifted along with the wafer 101 and can berotated to another station, e.g., in a multi-station system.

In an embodiment, an upper electrode within the showerhead 150 isgrounded when RF power is supplied from the RF power supply 104 to alower electrode within the pedestal 140.

In one embodiment, instead of the pedestal 140 being electricallycoupled to the RF power supply 104 via the match network 106, anelectrode within the showerhead 150 is coupled to the RF power supply104 via a match network for receiving power from the RF power supply 104and the lower electrode within the pedestal 140 is grounded.

In one embodiment, instead of the RF power supply 104, multiple RF powersupplies generating RF signals having different frequencies are used,e.g., a power supply for generating an RF signal having a frequency RF1and a power supply for generating an RF signal having a frequency RF2.

FIG. 2 illustrates a top view of a multi-station processing tool, wherefour processing stations are provided. This top view is of the lowerchamber portion 102 b (e.g., with the top chamber portion 102 a removedfor illustration), where four stations are accessed by spider forks 226.In one embodiment, there is no isolation wall or other mechanism toisolate one station from another. Each spider fork, or fork includes afirst and second arm, each of which is positioned around a portion ofeach side of the pedestal 140. In this view, the spider forks 226 aredrawn in dash-lines, to convey that they are below the carrier ring 200.The spider forks 226, using an engagement and rotation mechanism 220 areconfigured to raise up and lift the carrier rings 200 (i.e., from alower surface of the carrier rings 200) from the stationssimultaneously, and then rotate at least one or more stations beforelowering the carrier rings 200 (where at least one of the carrier ringssupports a wafer 101) to a next location so that further plasmaprocessing, treatment and/or film deposition can take place onrespective wafers 101.

FIG. 3 shows a schematic view of an embodiment of a multi-stationprocessing tool 300 with an inbound load lock 302 and an outbound loadlock 304. A robot 306, at atmospheric pressure, is configured to movesubstrates from a cassette loaded through a pod 308 into inbound loadlock 302 via an atmospheric port 310. Inbound load lock 302 is coupledto a vacuum source (not shown) so that, when atmospheric port 310 isclosed, inbound load lock 302 may be pumped down. Inbound load lock 302also includes a chamber transport port 316 interfaced with processingchamber 102 b. Thus, when chamber transport 316 is opened, another robot(not shown) may move the substrate from inbound load lock 302 to apedestal 140 of a first process station for processing.

The depicted processing chamber 102 b comprises four process stations,numbered from 1 to 4 in the embodiment shown in FIG. 3. In someembodiments, processing chamber 102 b may be configured to maintain alow pressure environment so that substrates may be transferred using acarrier ring 200 among the process stations without experiencing avacuum break and/or air exposure. Each process station depicted in FIG.3 includes a process station substrate holder (shown at 318 for station1) and process gas delivery line inlets.

FIG. 3 also depicts spider forks 226 for transferring substrates withinthe processing chamber 102 b, which is sometimes referred to herein as atool. As will be described in more detail below, the spider forks 226rotate and enable transfer of wafers from one station to another. Thetransfer occurs by enabling the spider forks 226 to lift carrier rings200 from an outer undersurface, which lifts the wafer, and rotates thewafer and carrier together to the next station. In one configuration,the spider forks 226 are made from a ceramic material to withstand highlevels of heat during processing.

FIG. 4A is a diagram of an embodiment of a plasma processing system 400to illustrate use of mutually induced filters with various components ofthe plasma processing system 400. The plasma processing system 400includes a pedestal 402, such as, for example, the pedestal 140 (FIG.1). The pedestal 402 includes a heater element HE1 and a heater elementHE2 for controlling temperature in different zones within a gap betweenthe showerhead 150 (FIG. 1) and the pedestal 140 (FIG. 1). Examples of aheater element include a resistor and a plate. The heater element HE1 isoperated to heat a portion of a component, e.g., an electrode, etc.,located within the pedestal 402 to control temperature of processing thewafer 101 (FIG. 1). The heater element HE2 is operated to heat anotherportion of the component located within the pedestal 402. For example,the component is located in contact with the heater elements HE1 and HE2to be heated by the heater elements HE1 and HE2.

A thermocouple TC1 is in contact with the heater element HE1 to sense atemperature of the heater element HE1 and a thermocouple TC2 is incontact with the heater elements HE2 to sense a temperature of theheater element HE2. Moreover, a motor is connected via one or moreconnection mechanisms, e.g., gears, shafts, links, etc., to the pedestal402 to rotate the pedestal 402 about a vertical axis z.

The plasma processing system 400 further includes a mutually inducedfilter 404A that are connected to the heater elements HE1 and HE2 and toAC power supplies AC1 and AC2, a mutually induced filter 404B that isconnected to the thermocouples TC1 and TC2 and to a temperaturecontroller, and a mutually induced filter 404C that is connected to themotor and to power supply.

It should be noted that a controller, as used herein, includes aprocessor and a memory device. Examples of the processor include amicroprocessor, an application specific integrated circuit (ASIC), aprogrammable logic device (PLD), and a central processing unit (CPU).Examples of the memory device include a read-only memory (ROM), a randomaccess memory (RAM), a flash memory, a storage disk array, a hard disk,etc.

The AC power supply AC1 supplies an AC signal to a first portion of themutually induced filter 404A, and the first portion filters RF powerfrom the AC signal to output a filtered signal. The filtered signal issent from the first portion of the mutually induced filter 404A to theheater element HE1 to heat the heater element HE1. Similarly, the ACpower supply AC2 supplies an AC signal to a second portion of themutually induced filter 404A and the second portion filters RF powerfrom the AC signal to output a filtered signal, which is sent from thesecond portion of the mutually induced filter 404A to the heater elementHE2 to heat the heater element HE2. It should be noted that RF powerthat is filtered from the AC signals supplied by the AC power suppliesAC1 and AC2 is coupled to the AC signals from RF power that is beingsupplied to the pedestal from the RF power supply 104. Such filteringreduces chances that RF power is coupled to a ground potential of the ACpower supplies AC1 and AC2. Furthermore, such filtering increaseschances of RF power being supplied to the pedestal instead of beinggrounded via the AC power supplies AC1 and AC2.

The thermocouple TC1 senses temperature of the heater element HE1 and togenerate a sensed temperature signal, which is provided to a firstportion of the mutually induced filter 404B for filtering RF power fromthe sensed temperature signal. RF power from the sensed temperaturesignal that passes through the first portion is filtered by the mutuallyinduced filter 404B to provide a filtered signal to the temperaturecontroller. Similarly, the thermocouple TC2 senses temperature of theheater element HE2 and to generate a sensed temperature signal, whichpasses via a second portion of the mutually induced filter 404B forfiltering RF power from the sensed temperature signal. RF power from thesensed temperature signal that passes through the second portion of themutually induced filter 404B is filtered by the mutually induced filter404B to provide a filtered signal to the temperature controller. Itshould be noted that RF power that is filtered from the sensedtemperature signals generated by the thermocouples TC1 and TC2 iscoupled with the sensed temperature signals from RF power that is beingsupplied to the pedestal from the RF power supply 104. Such filteringreduces a probability that the RF power that is coupled to the sensedtemperature signals will be supplied to the temperature controller anddamage the temperature controller. Furthermore, such filtering increaseschances of RF power being supplied to the pedestal instead of beingtransferred to the temperature controller.

The temperature controller includes a multimeter that receives thefiltered signal from the first portion of the mutually induced filter404B and provides a sensed value of the temperature of the heaterelement HE1 to the processor of the temperature controller. Theprocessor of the temperature controller determines whether to change,e.g., increase, decrease, etc., the temperature of the heater elementHE1 based on the sensed value. Upon determining that the temperature isto be changed, the temperature controller sends a signal indicating thechange in the temperature to the AC power supply AC1. Upon receiving thesignal for changing the temperature, the AC power supply AC1 generatesan AC signal for changing the temperature of the heater element HE1 andsends the AC signal via the first portion of the mutually induced filter404A to the heater element HE1.

Moreover, in a similar manner, the multimeter receives the filteredsignal from the second portion of the mutually induced filter 404B andprovides a sensed value of the temperature of the heater element HE2 tothe processor of the temperature controller. The processor of thetemperature controller determines whether to change the temperature ofthe heater element HE2 based on the sensed value. Upon determining thatthe temperature is to be changed, the temperature controller sends asignal indicating the change in the temperature to the AC power supplyAC2. Upon receiving the signal for changing the temperature, the ACpower supply AC2 generates an AC signal for changing the temperature ofthe heater element HE2 and sends the AC signal via the second portion ofthe mutually induced filter 404A to the heater element HE2.

The AC power source supplies AC power signals to the mutually inducedfilter 404C. The mutually induced filter 404C filters RF power from theAC power signals to generate filtered signals, which are sent from themutually induced filter 404C to the motor. A rotor of the motor rotateswith respect to a stator of the motor when the stator receives thefiltered signals. The rotational movement of the rotor is transferred tothe pedestal 402 via the one or more connection mechanisms. It should benoted that RF power that is filtered from the AC power signals generatedby the AC power source is coupled with the AC power signals from RFpower that is being supplied to the pedestal from the RF power supply104. Such filtering reduces chances that the RF power that is coupled tothe AC power signals will be supplied to the motor and cause damage tothe motor. Furthermore, such filtering increase chances of RF powerbeing supplied to the pedestal instead of being transferred to themotor.

In an embodiment, any number of heater elements are used in the pedestal402 to heat the component within the pedestal 402, and any number ofthermocouples are used to sense temperature of the heater elements.

In one embodiment, instead of the AC signal being supplied to the heaterelement HE1 from the AC power supply AC1 and the AC signal beingsupplied to the heater elements HE2 from the AC power supply AC2, a DCpower signal is supplied to the heater element HE1 from a DC powersupply and a DC power signal is supplied to the heater element HE2 froma DC power supply, and the DC power signals are filtered by a mutuallyinduced filter, embodiments of which are described herein.

In an embodiment, instead of AC power signals being supplied to themotor from the AC power source, DC power signals are supplied to themotor from a DC power source and RF power is filtered from the DC powersignals by using a mutually induced filter, embodiments of which aredescribed herein.

In one embodiment, instead of or in addition to the thermocouples TC1and TC2, two additional thermocouples are used for over temperatureprotection, e.g., in case temperatures of the heater elements HE1 andHE2 exceed a pre-determined temperature, etc. The two additionalthermocouples are connected to a mutually induced filter in a mannersimilar to that of connecting the mutually induced filter 404B to thethermocouples TC1 and TC2.

FIG. 4B is a circuit diagram of a mutually induced filter 410, which isan example of any of the mutually induced filters 404A, 404B, and 404C(FIG. 4A). The mutually induced filter 410 includes a portion 410A and aportion 410B.

The portion 410A includes a capacitor connected in series to an inductorand further includes two additional inductors, which are twisted andwound with the inductor coupled in series to the capacitor. In anembodiment, a mutually induced filter includes any other number ofinductors, e.g., one, three, etc., which are twisted and wound with theinductor coupled in series to the capacitor of the portion 410A.Moreover, in an embodiment, a mutually induced filter includes two ormore capacitors coupled in series with each other or in parallel witheach other instead of one capacitor shown in FIG. 4B. Similarly, theportion 410B includes a capacitor connected in series to an inductor andfurther includes two additional inductors, which are twisted and woundwith the inductor coupled in series to the capacitor of the portion410B.

It should be noted that a resonant frequency f1 of a series combinationof the capacitor and the inductor of the portion 410A is the same asthat of a resonant frequency f2 of a series combination of the capacitorand the inductor of the portion 410B. In one embodiment, the resonantfrequency f1 of the series combination of the capacitor and the inductorof the portion 410A is different from the resonant frequency f2 of theseries combination of the capacitor and the inductor of the portion410B. For example, the frequency f1 is a high frequency (HF) and thefrequency f2 is a low frequency (LF). As another example, the frequencyf1 is a low frequency and the frequency f2 is a high frequency. As yetanother example, the frequency f1 is a low or a high frequency and thefrequency f2 is between the high and low frequencies. As anotherexample, the frequency f2 is a low or a high frequency and the frequencyf1 is between the high and low frequencies. As another example, thefrequency f1 ranges between ±10% from 400 kilohertz (kHz), which is anexample of a low frequency, and the frequency f2 ranges between ±5% from13.56 megahertz (MHz), which is an example of a high frequency.

Wires of the mutually induced filter 410 are twisted together to formone unitary body and then wound to form inductors, which is also oneunitary body. For example, six wires are rotated around another wire andthe wires are then wound to form a unitary body having six inductorsthat are mutually coupled with each other. The resonant frequency f1 istransformed from the series combination of the capacitor and theinductor of the portion 410A to the remaining inductors of the mutuallyinduced filter 410. Similarly, the resonant frequency f2 of the seriescombination of the capacitor and the inductor of the portion 410B istransformed from the series combination to the remaining inductors ofthe mutually induced filter 410.

It should be noted that a block 411 around the inductors of the mutuallyinduced filter 410 that are not directly connected to the capacitors ofthe mutually induced filter 410 is shown to illustrate mutual inductancebetween the inductors.

As used herein, in one embodiment, twisting is to rotate two or morewires around each other, e.g., to form a strand, to form a braid-shapedstructure, etc., and wound is to form multiple turns, e.g., create aspiral, etc., of a coil.

In one embodiment, the capacitor and the inductor of the portion 410Bare excluded from the portion 410B. In an embodiment, the capacitor andthe inductor of the portion 410A are excluded from the portion 410A.

FIG. 4C is a diagram of an embodiment of the mutually induced filter 410in which the six wires are twisted and then wound together to form sixinductors. Two of the inductors are coupled with the capacitors of themutually induced filter 410 to form the mutually induced filter 410.

FIG. 5A is a diagram of an embodiment of the mutually induced filter 410coupled to resistors R1 and R2. The resistor R1 is an example of theheater element HE1 (FIG. 4A) and the resistor R2 is an example of theheater element HE2 (FIG. 4A). A node N1 of the resistor R1 is connectedto a channel C1 of the portion 410A, a node N2 of the resistor R1 isconnected to another channel C2 of the portion 410A, a node N3 of theresistor R2 is connected to a channel C3 of the portion 410B, and a nodeN4 of the resistor R2 is connected to a channel C4 of the portion 410B.The resistor R1 is used to heat a left portion of a lower electrode 502of the pedestal 402 and the resistor R2 is used to heat a right portionof the lower electrode 502.

A current signal supplied by the AC power supply AC1 is sent to aninductor of the channel C1. RF power is filtered by the mutually inducedfilter 410 at the resonant frequency f1 from the current signal that issupplied by the AC power supply AC1 to the resistor R1. The resonantfrequency f1 is coupled to the channel C1 from the inductor coupled inseries with the capacitor of the portion 410A to the inductor of thechannel C1. Moreover, RF power is filtered at the resonant frequency f1from a current signal that is returned from the resistor R1 via thechannel C2. The resonant frequency f1 is coupled to the channel C2 fromthe inductor coupled in series with the capacitor of the portion 410Avia the inductor of the channel C1 to the inductor of the channel C2.Also, RF power is filtered at the resonant frequency f2 from the currentsignal supplied by the AC power supply AC1 to the resistor R1. Theresonant frequency f2 is coupled to the channel C1 from the inductorcoupled in series with the capacitor of the portion 410B via theinductor of the channel C4, the inductor of the channel C3, and theinductor of the channel C2, to the inductor of the channel C1.Furthermore, RF power is filtered at the resonant frequency f2 from acurrent signal that is returned from the resistor R1 via the channel C2.The resonant frequency f2 is coupled to the channel C2 from the inductorcoupled in series with the capacitor of the portion 410B via theinductor of the channel C4 and the inductor of the channel C3 to theinductor of the channel C2.

A current signal supplied by the AC power supply AC2 is sent to aninductor of the channel C4. RF power is filtered by the mutually inducedfilter 410 at the resonant frequency f1 from the current signal that issupplied by the AC power supply AC2 to the resistor R2. The resonantfrequency f1 is coupled to the channel C4 from the inductor coupled inseries with the capacitor of the portion 410A via the inductor of thechannel C1, the inductor of the channel C2, and the inductor of thechannel C3 to the inductor of the channel C4. Moreover, RF power isfiltered at the resonant frequency f1 from a current signal that isreturned from the resistor R2 via the channel C3. The resonant frequencyf1 is coupled to the channel C3 from the inductor coupled in series withthe capacitor of the portion 410A via the inductor of the channel C1 andthe inductor of the channel C2 to the inductor of the channel C3. Also,RF power is filtered at the resonant frequency f2 from the currentsignal supplied by the AC power supply AC2 to the resistor R2. Theresonant frequency f2 is coupled to the channel C4 from the inductorcoupled in series with the capacitor of the portion 410B to the inductorof the channel C4. Furthermore, RF power is filtered at the resonantfrequency f2 from a current signal that is returned from the resistor R2via the channel C3. The resonant frequency f2 is coupled to the channelC3 from the inductor coupled in series with the capacitor of the portion410B via the inductor of the channel C4 to the inductor of the channelC3.

FIG. 5B is a diagram of an embodiment of the mutually induced filter 410coupled to the thermocouples TC1 and TC2. A sensed temperature signal issent from a sensing junction SJ1 of the thermocouple TC1 via a portionof the channel C1 of the portion 410A to the inductor of the channel C1.Moreover, a reference temperature signal is sent from a referencejunction RJ1 of the thermocouple TC1 via a portion of the channel C2 ofthe portion 410A to the inductor of the channel C2.

The resonant frequency f1 of the series combination of the capacitor andthe inductor of the portion 410A is coupled from the inductor of thechannel C1 via the inductor of the channel C2 and the inductor of thechannel C3 to the inductor of the channel C4. Similarly, the resonantfrequency f2 of the series combination of the capacitor and the inductorof the portion 410B is coupled from the inductor of the channel C4 viathe inductor of the channel C3 and the inductor of a channel C2 to theinductor of the channel C1. RF power from the reference temperaturesignal sent from the reference junction RJ1 and from the sensedtemperature signal sent from the sensing junction SJ1 is filtered by theportion 410A at the resonant frequencies f1 and f2 to generate filteredsignals, which are used by the temperature controller to determine,e.g., measure, etc., a temperature of the resistor R1.

Similarly, a sensed temperature signal is sent from a sensing junctionSJ2 of the thermocouple TC2 via the channel C4 of the portion 410B tothe inductor of the channel C4. Moreover, a reference temperature signalis sent from a reference junction RJ2 of the thermocouple TC2 via thechannel C3 of the portion 410B to the inductor of the channel C3. RFpower from the reference temperature signal sent from the referencejunction RJ2 and from the sensed temperature signal sent from thesensing junction SJ2 is filtered by the portion 410B at the resonantfrequencies f1 and f2 to generate filtered signals, which are used bythe temperature controller to determine a temperature of the resistorR2.

FIG. 5C is a diagram of an embodiment of the mutually induced filter 410coupled to the motor and the AC power source. It should be noted that afirst phase of an AC signal is supplied from the AC power source via thechannel C1 of the portion 410A to a winding of stator of the motor and afirst phase of an AC signal is returned from the winding to the AC powersource via the channel C2 of the portion 410A. Moreover, a second phaseof the supplied AC signal is provided from the AC power source via thechannel C4 of the portion 410B to another winding of the stator of themotor and a second phase of the returned AC signal is sent from theother winding to the AC power source via the channel C3 of the portion410B.

The resonant frequency f1 of the series combination of the capacitor andthe inductor of the portion 410A is coupled from the inductor of theportion 410A via the inductor of the channel C1, the inductor of thechannel C2, and the inductor of the channel C3 to the inductor of thechannel C4. Similarly, the resonant frequency f2 of the seriescombination of the capacitor and the inductor of the portion 410B iscoupled from the inductor or the portion 410B via the inductor of thechannel C4, the inductor of the channel C3, and the inductor of thechannel C2 to the inductor of the channel C1.

When the resonant frequency f1 is coupled with the portion 410B from theportion 410A, RF power from the first and second phases of the suppliedAC signals and from the first and second phases of the returned ACsignals is filtered by the mutually induced filter 410 at the resonantfrequency f1. Moreover, when the resonant frequency f2 is coupled withthe portion 410A from the portion 410B, RF power from the first andsecond phases of the supplied AC signals and from the first and secondphases of the returned AC signals is filtered by the mutually inducedfilter 410 at the resonant frequency f2.

The above embodiment of the mutually induced filter 410 is associatedwith providing a two-phase AC signal to the motor. In one embodiment inwhich a three-phase AC signal is supplied by the AC power source to themotor, a third phase of the supplied AC signal is provided from the ACpower source via a channel (not shown) of a mutually induced filter (notshown) to a winding of the stator of the motor and a third phase of thereturned AC signal is returned from the winding of the stator to the ACpower source via a channel of the mutually induced filter. Inductors ofthe mutually induced filter used to filter RF power from the third phaseof the AC signal are mutually coupled with the inductors that are usedto filter RF power from the first and second phases of the AC signal andthe mutually coupling facilitates filtering of RF power from the thirdphase by the mutually induced filter at the resonant frequencies f1 andf2. Moreover, in case a series combination, of a capacitor and aninductor, having a resonant frequency f3 is coupled to an inductor ofthe mutually induced filter used to filter RF power from the thirdphase, there is mutual coupling between the portions 410A and 410B, anda portion that includes the capacitor and the inductors associated withfiltering RF power from the third phase. The mutual coupling between theportion 410A, the portion 410B, and the portion facilitates filtering ofRF power by the portions 410A and 410B and the portion at the resonantfrequency f3.

FIG. 5D is a diagram of an embodiment of the mutually induced filter 410coupled to the resistors R1 and R2, the mutually induced filter 410coupled to the thermocouples TC1 and TC1, and the mutually inducedfilter 410 coupled to the motor.

FIG. 6 is a diagram of an embodiment of a mutually induced filter 602,which includes a portion 602A and a portion 602B, to illustrate mutualcoupling between the portions 602A and 602B. The portion 602A isconnected to a load element LE1, e.g., the heater element HE1, or awinding of a stator of a motor, the thermocouple TC1, etc., and theportion 602B is connected to a corresponding load element LE2, e.g., theheater element HE2, or another winding of the stator of the motor, orthe thermocouple TC2, etc. The portion 602A includes passive components,e.g., a plurality of inductors I1 and I2 and a capacitor, etc., whichare coupled with each other. The capacitor of the portion 602A iscoupled in series with the inductor H. Moreover, the portion 602Bincludes passive components, e.g., a plurality of inductors I3 and I4and a capacitor, etc., which are coupled with each other. The inductorI4 of the portion 602B is coupled in series with the capacitor of theportion 602B. Moreover, the inductors I1, I2, I3, and I4 are twisted andwound with each other so that mutual coupling is achieved between theinductors I1, I2, I3, and I4. When the mutually coupling is established,a resonant frequency of a combination of the capacitor of the portion602A and the inductor I1 is transferred via the inductor I2 and theinductor I3 to the inductor I4 and a resonant frequency of a combinationof the capacitor of the portion 602B and the inductor I4 is transferredvia the inductor I3 and the inductor I2 to the inductor I1.

When the load element LE1 is a heater element, a node of the loadelement LE1 is coupled via the inductor I1 to a power supply, e.g., anAC power supply, a DC power supply, etc., and another node of the loadelement LE1 is coupled via the inductor I2 to the power supply.Moreover, when the load element LE2 is a heater element, a node of theload element LE2 is coupled via the inductor I4 to a power supply andanother node of the load element LE2 is coupled via the inductor I3 tothe power supply. When the load element LE1 is a stator winding of themotor, a node of the load element LE1 is coupled via the inductor I1 toa power source, e.g., the AC power source, the DC power source, etc.,and another node of the load element LE1 is coupled via the inductor I2to the power source. Moreover, when the load element LE2 is a statorwinding of the motor, a node of the load element LE2 is coupled via theinductor I4 to the power source and another node of the load element LE2is coupled via the inductor I3 to the power source.

During operation, a signal, e.g., an AC signal, a DC signal, etc., istransferred via the inductors I1 and I2 of the portion 602A and asignal, e.g., an AC signal, a DC signal, etc., is transferred via theinductors I3 and I4 of the portion 602B. A combination of the capacitorof the portion 602A and the inductor I1 operates at the resonancefrequency f1. Also, a combination of the capacitor of the portion 602Band the inductor I4 operates at the resonance frequency f2. The transferof the signal via the inductor I1 generates an electromagnetic field,which couples with the inductors I2, I3 and I4. The transfer of thesignal via the inductor I4 generates another electromagnetic field,which couples with the inductors I3, I2, and I1. The electromagneticfield generated by the transfer of the signal via the inductor I1creates a voltage across the inductor I2, a voltage across the inductorI3, and a voltage across the inductor I4 and in an embodiment, thecreation of the voltages is sometimes referred to herein as mutualcoupling. Similarly, the electromagnetic field generated by the transferof the signal via the inductor I4 creates a voltage across the inductorI3, a voltage across the inductor I2, and a voltage across the inductorI1, and in some embodiments, the creation of the voltage is sometimesreferred to herein as mutual coupling.

When mutual coupling is achieved between the portion 602A and theportion 602B, the filter 602 operates at or close to, e.g., within 2percent of, etc., the resonant frequency f1 of the series combination ofthe capacitor of the portion 602A and the inductor I1 and at or close tothe resonant frequency f2 of the series combination of the capacitor ofthe portion 602B and the inductor I4. For example, when a coefficient ofcoupling k between the portions 602A and 602B is 1 or close to 1, e.g.,greater than 0.9, etc., the mutually induced filter 602 operates at theresonant frequencies f1 and f2.

It should be noted that RF power from the signals that are transferredvia the portions 602A and 602B is filtered by the filter 602. Forexample, RF power from an AC signal that is supplied from the AC powersource to the motor and from an AC signal that is received from themotor is filtered by the filter 602. As another example, RF power froman AC signal that is supplied from an AC power supply to the heaterelement HE1 and from an AC signal that is received from the heaterelement HE1 is filtered by the filter 602.

In one embodiment, the load element LE1 is a thermocouple and a node,e.g., a sensing junction, etc., of the load element LE1 is coupled tothe temperature controller via the inductor I1 and another node, e.g., areference junction, etc., of the load element LE1 is coupled to thetemperature controller via the inductor I2. RF power from a signal thatis received from the sensing junction of the load element LE1 and from asignal that is received from the reference junction of the load elementLE1 is filtered by the filter 602. Similarly, in the embodiment, theload element LE2 is a thermocouple and a node, e.g., a sensing junction,etc., of the load element LE2 is coupled to the temperature controllervia the inductor I3 of the portion 602B and another node, e.g., areference junction, etc., of the load element LE2 is coupled to thetemperature controller via the inductor I4 of the portion 602B. RF powerfrom an AC signal that is received from the sensing junction of the loadelement LE2 and from an AC signal that is received from the referencejunction of the load element LE2 is filtered by the filter 602.

In one embodiment, the capacitor of the portion 602B is excluded fromthe filter 602. In this embodiment, the filter 602 operates at theresonant frequency f1 of the series combination of the capacitor of theportion 602A and the inductor I1.

In an embodiment, the capacitor of the portion 602A is excluded from thefilter 602. In this embodiment, the filter 602 operates at the resonantfrequency f2 of the series combination of the capacitor of the portion602B and the inductor I4.

FIG. 7 is a diagram of an embodiment of a mutually induced filter 702 toillustrate that mutual coupling is achieved between portions 702A and702B that are used to filter RF power from AC signals transferredbetween the heater elements HE1 and HE2 and the AC power supplies AC1and AC2. The portions 702A and 702B are also used to filter RF powerfrom AC signals transferred between the motor and the AC power source.The portions 702A and 702B are collectively referred to as the mutuallyinduced filter 702.

Inductors I1, I2, I3, I4, I5, I6, I7, I8, I9, and I10 of the mutuallyinduced filter 702 are twisted together to mutually couple theinductors. The resonant frequency f1 of the series combination of thecapacitor and the inductor of the portion 702A is coupled from theinductor I1 via the inductors I2 thru I9 to the inductor I10 to mutuallycouple the resonant frequency f1 to the portion 702B from the portion702A. Moreover, the resonant frequency f2 of the series combination ofthe capacitor and the inductor I10 of the portion 702B is coupled fromthe inductor I10 via the inductors I9, I8, I7, I6, I5, I4, I3, and I2 tothe inductor I1 to mutually couple the resonant frequency f2 to theportion 702A from the portion 702B.

It should be noted that a block 703 around the inductors I2 thru I9 isshown to illustrate mutual inductance between the inductors.

In one embodiment, instead of the portion 702B being coupled to themotor and the AC power source, the portion 702B is coupled between thethermocouples TC1 and TC2 and the temperature controller. The portion702B filters signals that are sensed by the thermocouples TC1 and TC2.

It should be noted that in one embodiment, instead of the heaterelements HE1 and HE2 being coupled to the AC power supplies AC1 and AC2,the heater elements are coupled to DC power supplies. In an embodiment,instead of the motor being coupled to the AC power source, the motor iscoupled to the DC power source.

FIG. 8A is an embodiment of a graph 800 and FIG. 8B is an embodiment ofa circuit diagram of a mutually induced filter 804 to illustrate thatthe resonant frequency f1 is transferred from a serially-coupled sectionS1 of the portion 804A via the inductor I1 and the inductor I2 to theinductor I3. The mutually induced filter includes portions 804A and804B. The graph 800 plots attenuation of RF power in decibels (dB)caused by the serially-coupled section S1 of the portion 804A, caused bythe inductor I1, caused by the inductor I2, and caused by the inductorI3 versus frequency, which is calculated in megahertz (MHz). Mutualcoupling between inductors I0 thru I3 results in coupling of theresonant frequency f1 of the series combination of the capacitor and theinductor I0 of the serially-coupled section S1 from the inductor I0 tothe inductors I1, I2, and I3.

It should be noted that the graph 800 represents attenuation of RF powerby each of the inductors I1 thru I3 that are twisted with each other andwith the inductor I0, and represents attenuation by the serially-coupledsection S1. The twisting is performed manually. In case the twisting isdone using a machine, and the inductors I0 thru I3 have the sameinductance, e.g., the same length, the same wire diameter, same numberof windings, same pitch of twisting each wire for each inductor, samematerial, etc., the attenuation provided by the serially-coupled sectionS1 and the inductors I1 thru I3 is the same or substantially the same.

Moreover, when two inductors are twisted with a defined pitch, mutualinductance is the same or substantially the same, e.g., within 2percent, etc., as that of individual inductance of each of theinductors. The mutual inductance increases inductance offered by eachinductor by two times if the mutual inductance is the same as theindividual inductance. Also, parasitic coupling between the twoinductors is the same or substantially the same, e.g., within 2 percent,etc.

It should be noted that a block 803 around the inductors I1 thru I3 isshown to illustrate mutual inductance between the inductors.

Furthermore, it should be noted that in one embodiment, one end of theinductor I0 of the serially-coupled section S1 is coupled to the heatingelement HE1 and to the capacitor of the serially-coupled section S1 andanother end of the inductor I0 is coupled to a power supply, e.g., theAC power supply AC1, a DC power supply DC1, etc., and to the capacitorof the serially-coupled section S1. Also, the inductor I1 is connectedto the heating element HE1 at one end and to the power supply, e.g., theAC power supply AC1, the DC power supply DC1, etc., at the other end.The inductor I2 is connected to the heating element HE2 at one end andto a power supply, e.g., the AC power supply AC2, a DC power supply DC2,etc., at another end of the inductor I2. The inductor I3 is connected tothe heating element HE2 at one end and to the power supply, e.g., the ACpower supply AC2, the DC power supply DC2, etc., at the other end of theinductor I3.

In an embodiment, one end of the inductor I0 is coupled to the sensingjunction of the thermocouple TC1 and to the capacitor of theserially-coupled section S1 and another end of the inductor I0 iscoupled to the temperature controller and to the capacitor of theserially-coupled section S1. Also, in this embodiment, the inductor I1is connected to the reference junction of the thermocouple TC1 at oneend and to the temperature controller at another end. The inductor I2 isconnected to the sensing junction of the thermocouple TC2 at one end andto the temperature controller at another end. The inductor I3 isconnected to the reference junction of the thermocouple TC2 at one endand to the temperature controller at another end.

In an embodiment, one end of the inductor I0 is coupled to a firstwinding of the stator of the motor and to the capacitor of theserially-coupled section S1 and another end of the inductor I0 iscoupled to the first phase of a power source, e.g., the AC power source,the DC power source, etc., and to the capacitor of the serially-coupledsection S1. Also, the inductor I1 is connected to the first winding atone end and to the power source at another end. The inductor I2 isconnected to a second winding of the stator at one end and to the ACpower source at another end. The inductor I3 is connected to the secondwinding at one end and to the AC power source at another end.

FIG. 9 is a diagram illustrating a cross-section of a mutually inducedfilter 900, e.g., an inductor, etc. The mutually induced filter 900includes a filter component 902, e.g., an inductor coupled to acapacitor, etc., and multiple inductors 904A, 904B, 904C, and 904D. Awire of each of the inductors 904A thru 904D is thicker than a wire ofthe inductor of the filter element 902. For example, a diameter d1 ofthe filter component 902, e.g., an inductor, etc., is less than adiameter d2 of each of the inductors 904A thru 904D. In one embodiment,diameters of the inductors 904A thru 904D are different from each otherand the diameters are greater than the diameter d1. A minimal amount ofcurrent passes through the filter element 902 and a higher amount ofcurrent passes through each of the inductors 904A thru 904D. The higheramount of current is an amount that is greater than the minimal amountof current. For example, each of inductors 904A and 904C is connected toa separate power supply, e.g., an AC power supply, a DC power supply,etc., for receiving a signal from the power supply and each of inductors904B and 904D provides a path for return of a signal from a separateresistive element. When there is mutually coupling between the inductorsof the filter element and the inductors 904A thru 904D, the mutuallyinduced filter 900 filters RF power from supply signals generated by thepower supplies connected to the inductors 904A and 904C and also filtersRF power from return signals that is returned from the resistiveelements. RF power from the supply and return signals is filtered at aresonant frequency of the filter element 902. To achieve the mutualcoupling, the wire of the filter element 902 is twisted with wires ofthe inductors 904A thru 904D and then wound to form the inductor of thefilter elements 902 and the inductors 904A thru 904D, and then theinductor of the filter element 902 is connected to the capacitor of tofabricate the mutually induced filter 900. As another example, theinductors 904A and 904C are connected to reference junctions of twothermocouples and the inductors 904B and 904D are connected to sensingjunctions of the thermocouples. RF power from signals generated when thethermocouples sense temperature differences are filtered by the filterelement 902. As yet another example, each inductor 904A and 904C isconnected to a power source, e.g., the AC power source, the DC powersource, etc., and each inductor 904B and 904D provides a path for returnfrom a separate stator winding of the motor. The filter element 902filters RF power from signals generated by the power source connected tothe inductors 904A and 904C and also filters RF power from returnsignals that are returned from the stator windings.

The use of the filter element 902 that is not directly connected to apower supply or a power source or to a resistive element or to a windingprotects the filter element 902 from excessive current. Also, themutually induced filter 900 in which the filter element 902 has asmaller cross-sectional thickness is more compact than a package inwhich a filter element is of the same thickness as that of each of theinductors 904A, 904B, 904C, and 904D.

FIG. 10A is a diagram of an embodiment of a graph 1000 for illustratingsimilar attenuation of RF power by mutually coupled inductors andexhibition of same resonant frequencies f1 and f2 by components of amutually induced filter 1002. The graph 1000 illustrates attenuation ofRF power by an inductor and a capacitor of a channel 1, an inductor of achannel 2, an inductor of a channel 3, and an inductor and a capacitorof a channel 4. The inductors and the capacitors are of the mutuallyinduced filter 1002, a prototype of which is illustrated in FIG. 10B-1.Band rejection filtering characteristics of the mutually induced filter1002 are illustrated in FIG. 10A. Also, a circuit diagram of themutually induced filter 1002 is illustrated in FIG. 10B-2.

As shown in the prototype, four inductors are fabricated by twistingfour wires to form a unitary body, which is then wound to change theshape of the unitary body from straight to spiral to change a shape ofthe unitary body. A first one of the four inductors is connected inseries to two capacitors and a second one of the four inductors isconnected in series with a single capacitor to fabricate the prototypeof the mutually induced filter 1002. The two capacitors are connected inparallel with each other, and a combination of the two capacitors andthe inductor that is connected in series with the two capacitors have aresonant frequency f3. A combination of the second inductor and thecapacitor that is connected in series with the second inductor have aresonant frequency f4.

The inductor of the channel 3 is mutually coupled with the inductors ofthe channels 1, 2, and 4 and the mutual coupling results in coupling ofthe resonant frequency f3 from the inductor of the channel 3 to theinductors of the channels 1, 2, and 4. Also, the inductor of the channel2 is mutually coupled with the inductors of the channels 1, 3, and 4 andthe mutual coupling results in coupling of the resonance frequency f4from the inductor of the channel 2 to the inductors of the channels 1,3, and 4. Mutual coupling between the inductors of the channels 1, 2, 3,and 4 results in similar or the same attenuation by the inductor and thecapacitors of the channel 3, the inductor of the channel 1, the inductorof the channel 4, and the inductor and the capacitor of the channel ofthe channel 2.

It should be noted that a block 1003 around the inductors connected tothe channels 1 and 4 is shown to illustrate mutual inductance betweenthe inductors.

It should be noted that as shown in the graph 1000, attenuation providedby the inductor and the capacitors of the channel 3 at the frequency f3is greater, e.g., more negative, etc., than attenuations provided by theinductors of the channels 1 and 4 at the frequency f3. The capacitors ofthe channel 3 increase the attenuation associated with the channel 3compared to attenuation provided by the channel 1 or 4. Similarly,attenuation provided by the inductor and the capacitor of the channel 2at the frequency f4 is greater than attenuations provided by theinductors of the channels 1 and 4 at the frequency f4. The capacitor ofthe channel 2 increases the attenuation provided by the channel 2compared to attenuation provided by the channel 1 or 4. Differencebetween an attenuation provided by a channel that is connected to acapacitor and a channel that is not, e.g., a channel connected to aninductor without being connected to a capacitor, etc., depends upon avariable K, which is a ratio of L and M, where L is inductance of theeach inductor of each channel and M is a mutual inductance between thetwo inductors. Moreover, the difference depends upon parameters of wiresof the inductors, e.g., resistive loss of wires of the inductors, etc.

It should further be noted that in one embodiment, if inductance of eachof the inductors of the channels 1 and 4 is the same, e.g., theinductors have the same wire diameter, the same wire length, the samewire material, etc., and if the mutual coupling is 100% or substantiallyclose to 100%, e.g., 99% to 100%, etc., attenuation provided by theinductors of the channels 1 and 4 is the same or substantially the same,e.g., within 2%, etc., at each of the frequencies f3 and f4.

In an embodiment, f3 is different from f4. In one embodiment, f3 is thesame as f4.

It should further be noted that although two frequencies f3 and f4 areshown, in one embodiment, more than two frequencies are used. Forexample, in case of N+M channels, M is a number of resonant frequenciesand N is a number of outputs of the channels. Each of N and M is aninteger greater than zero. The outputs either receive power from a powersupply or a power source or supply power to a load.

In one embodiment, instead of the two capacitors of the channel 3 beingcoupled to each other in parallel, one capacitor is used or any othernumber of capacitors is coupled in parallel. In an embodiment, insteadof the two capacitors of the channel 3 being coupled to each other inparallel, the two capacitors of any other number of capacitors arecoupled in series with each other.

Similarly, in an embodiment, instead of the capacitor of the channel 2,a number of capacitors coupled in series with each other or parallel toeach other is used.

FIGS. 11A, 11B, 11C, and 11D show embodiments of graphs 1102, 1104,I106, and 1108 to illustrate attenuations associated with the channels1, 2, 3, and 4 separately. Data within the graph 1000 (FIG. 10A) issegregated to provide for better visibility of data associated with eachchannel 1, 2, 3, and 4 in the graphs 1102, 1104, 1106, and 1108.

FIG. 12 is a diagram to illustrate twisting and winding of fourinductors I1 thru I4 to create a portion of a mutually induced filter.As shown, four wires are twisted with each other at a defined pitch andthen are wound to form the four inductors I1 thru I4 that are mutuallycoupled with each other to form a portion of a mutually induced filter.

In an embodiment, any number of inductors, other than four, is twistedat a pre-defined pitch and is wound to form a portion of a mutuallyinduced filter.

Embodiments described herein may be practiced with various computersystem configurations including hand-held hardware units, microprocessorsystems, microprocessor-based or programmable consumer electronics,minicomputers, mainframe computers and the like. The embodiments canalso be practiced in distributed computing environments where tasks areperformed by remote processing hardware units that are linked through anetwork.

In some embodiments, a controller is part of a system, which may be partof the above-described examples. Such systems include semiconductorprocessing equipment, including a processing tool or tools, chamber orchambers, a platform or platforms for processing, and/or specificprocessing components (a wafer pedestal, a gas flow system, etc.). Thesesystems are integrated with electronics for controlling their operationbefore, during, and after processing of a semiconductor wafer orsubstrate. The electronics is referred to as the “controller,” which maycontrol various components or subparts of the system or systems. Thecontroller, depending on the processing requirements and/or the type ofsystem, is programmed to control any of the processes disclosed herein,including the delivery of process gases, temperature settings (e.g.,heating and/or cooling), pressure settings, vacuum settings, powersettings, RF generator settings, RF matching circuit settings, frequencysettings, flow rate settings, fluid delivery settings, positional andoperation settings, wafer transfers into and out of a tool and othertransfer tools and/or load locks connected to or interfaced with asystem.

Broadly speaking, in a variety of embodiments, the controller is definedas electronics having various integrated circuits, logic, memory, and/orsoftware that receive instructions, issue instructions, controloperation, enable cleaning operations, enable endpoint measurements, andthe like. The integrated circuits include chips in the form of firmwarethat store program instructions, digital signal processors (DSPs), chipsdefined as ASICs, PLDs, and/or one or more microprocessors, ormicrocontrollers that execute program instructions (e.g., software). Theprogram instructions are instructions communicated to the controller inthe form of various individual settings (or program files), definingoperational parameters for carrying out a particular process on or for asemiconductor wafer or to a system. The operational parameters are, insome embodiments, a part of a recipe defined by process engineers toaccomplish one or more processing steps during the fabrication of one ormore layers, materials, metals, oxides, silicon, silicon dioxide,surfaces, circuits, and/or dies of a wafer.

The controller, in some embodiments, is a part of or coupled to acomputer that is integrated with, coupled to the system, otherwisenetworked to the system, or a combination thereof. For example, thecontroller is in a “cloud” or all or a part of a fab host computersystem, which allows for remote access of the wafer processing. Thecomputer enables remote access to the system to monitor current progressof fabrication operations, examines a history of past fabricationoperations, examines trends or performance metrics from a plurality offabrication operations, to change parameters of current processing, toset processing steps to follow a current processing, or to start a newprocess.

In some embodiments, a remote computer (e.g. a server) provides processrecipes to a system over a network, which includes a local network orthe Internet. The remote computer includes a user interface that enablesentry or programming of parameters and/or settings, which are thencommunicated to the system from the remote computer. In some examples,the controller receives instructions in the form of data, which specifyparameters for each of the processing steps to be performed during oneor more operations. It should be understood that the parameters arespecific to the type of process to be performed and the type of toolthat the controller is configured to interface with or control. Thus asdescribed above, the controller is distributed, such as by including oneor more discrete controllers that are networked together and workingtowards a common purpose, such as the processes and controls describedherein. An example of a distributed controller for such purposesincludes one or more integrated circuits on a chamber in communicationwith one or more integrated circuits located remotely (such as at theplatform level or as part of a remote computer) that combine to controla process on the chamber.

Without limitation, in various embodiments, example systems include aplasma etch chamber or module, a deposition chamber or module, aspin-rinse chamber or module, a metal plating chamber or module, a cleanchamber or module, a bevel edge etch chamber or module, a physical vapordeposition (PVD) chamber or module, a chemical vapor deposition (CVD)chamber or module, an atomic layer deposition (ALD) chamber or module,an atomic layer etch (ALE) chamber or module, an ion implantationchamber or module, a track chamber or module, and any othersemiconductor processing systems that is associated or used in thefabrication and/or manufacturing of semiconductor wafers.

It is further noted that in some embodiments, the above-describedoperations apply to several types of plasma chambers, e.g., a plasmachamber including an inductively coupled plasma (ICP) reactor, atransformer coupled plasma chamber, a capacitively coupled plasmareactor, conductor tools, dielectric tools, a plasma chamber includingan electron cyclotron resonance (ECR) reactor, etc.

As noted above, depending on the process step or steps to be performedby the tool, the controller communicates with one or more of other toolcircuits or modules, other tool components, cluster tools, other toolinterfaces, adjacent tools, neighboring tools, tools located throughouta factory, a main computer, another controller, or tools used inmaterial transport that bring containers of wafers to and from toollocations and/or load ports in a semiconductor manufacturing factory.

With the above embodiments in mind, it should be understood that some ofthe embodiments employ various computer-implemented operations involvingdata stored in computer systems. These operations are those physicallymanipulating physical quantities. Any of the operations described hereinthat form part of the embodiments are useful machine operations.

Some of the embodiments also relate to a hardware unit or an apparatusfor performing these operations. The apparatus is specially constructedfor a special purpose computer. When defined as a special purposecomputer, the computer performs other processing, program execution orroutines that are not part of the special purpose, while still beingcapable of operating for the special purpose.

In some embodiments, the operations may be processed by a computerselectively activated or configured by one or more computer programsstored in a computer memory, cache, or obtained over the computernetwork. When data is obtained over the computer network, the data maybe processed by other computers on the computer network, e.g., a cloudof computing resources.

One or more embodiments can also be fabricated as computer-readable codeon a non-transitory computer-readable medium. The non-transitorycomputer-readable medium is any data storage hardware unit, e.g., amemory device, etc., that stores data, which is thereafter be read by acomputer system. Examples of the non-transitory computer-readable mediuminclude hard drives, network attached storage (NAS), ROM, RAM, compactdisc-ROMs (CD-ROMs), CD-recordables (CD-Rs), CD-rewritables (CD-RWs),magnetic tapes and other optical and non-optical data storage hardwareunits. In some embodiments, the non-transitory computer-readable mediumincludes a computer-readable tangible medium distributed over anetwork-coupled computer system so that the computer-readable code isstored and executed in a distributed fashion.

Although the method operations above were described in a specific order,it should be understood that in various embodiments, other housekeepingoperations are performed in between operations, or the method operationsare adjusted so that they occur at slightly different times, or aredistributed in a system which allows the occurrence of the methodoperations at various intervals, or are performed in a different orderthan that described above.

It should further be noted that in an embodiment, one or more featuresfrom any embodiment described above are combined with one or morefeatures of any other embodiment without departing from a scopedescribed in various embodiments described in the present disclosure.

Although the foregoing embodiments have been described in some detailfor purposes of clarity of understanding, it will be apparent thatcertain changes and modifications can be practiced within the scope ofappended claims. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the embodiments arenot to be limited to the details given herein, but may be modifiedwithin the scope and equivalents of the appended claims.

The invention claimed is:
 1. A mutually induced filter for filteringradio frequency (RF) power from signals supplied to a load, comprising:a first portion connected to a first load element of the load forfiltering RF power from one of the signals supplied to the first loadelement, wherein the load is associated with a pedestal of a plasmachamber; and a second portion connected to a second load element of theload for filtering RF power from another one of the signals supplied tothe second load element, wherein the first and second portions aretwisted with each other to be mutually coupled with each other tofurther facilitate a coupling of a first resonant frequency associatedwith the first portion to the second portion, wherein the first portionincludes three or more inductors twisted with each other and one of thethree or more inductors of the first portion is connected in series to afirst capacitor without being connected to a power supply, whereinremaining two of the three or more inductors are coupled to the powersupply.
 2. The mutually induced filter of claim 1, wherein the secondportion includes a plurality of inductors, wherein the inductors of thesecond portion are coextensively twisted with the three or moreinductors of the first portion to define one unitary wound body.
 3. Themutually induced filter of claim 1, wherein the first and secondportions are twisted with each other to facilitate a coupling of asecond resonant frequency associated with the second portion to thefirst portion.
 4. The mutually induced filter of claim 1, wherein thesecond portion includes three or more inductors twisted with each otherand one of the three or more inductors of the second portion isconnected to a second capacitor, wherein the three or more inductors ofthe second portion are twisted with the three or more inductors of thefirst portion to achieve the mutual coupling between the first andsecond portions to further achieve the coupling of the first resonantfrequency.
 5. The mutually induced filter of claim 4, wherein acombination of the first capacitor of the first portion and the one ofthe three or more inductors of the first portion has the first resonantfrequency and a combination of the second capacitor of the secondportion and the one of the three or more inductors of the second portionhas a second resonant frequency, wherein both the first and secondresonant frequencies are the same, wherein the mutual coupling betweenthe first and second portions facilitates a coupling of the secondresonant frequency from the second portion to the first portion.
 6. Themutually induced filter of claim 4, wherein a combination of the firstcapacitor of the first portion and the one of the three or moreinductors of the first portion has the first resonant frequency and acombination of the second capacitor of the second portion and the one ofthe three or more inductors of the second portion has a second resonantfrequency, wherein both the first and second resonant frequencies aredifferent from each other, wherein the mutual coupling between the firstand second portions facilitates a coupling of the second resonantfrequency from the second portion to the first portion.
 7. The mutuallyinduced filter of claim 1, wherein the second portion includes three ormore inductors twisted with each other, wherein the three or moreinductors of the second portion are twisted with the three or moreinductors of the first portion to achieve the mutual coupling betweenthe first and second portions.
 8. The mutually induced filter of claim1, wherein the remaining two inductors of the first portion areconnected to the first load element.
 9. The mutually induced filter ofclaim 1, wherein each of the first and second load element is aresistive element or a winding of a stator of a motor.
 10. A mutuallyinduced filter for filtering radio frequency (RF) power from signalsreceived from a load, comprising: a first portion connected to a firstload element of the load for filtering RF power from one of the signalsreceived from the first load element, wherein the load is associatedwith a pedestal of a plasma chamber; and a second portion connected to asecond load element of the load for filtering RF power from another oneof the signals received from the second load element, wherein the firstload element is a thermocouple connected to a first heater element ofthe plasma chamber to sense a temperature of the first heater element,wherein the second load element is a thermocouple connected to a secondheater element of the plasma chamber to sense a temperature of thesecond heater element, wherein the first and second portions are twistedwith each other to be mutually coupled with each other to furtherfacilitate a coupling of a first resonant frequency associated with thefirst portion to the second portion, wherein the first portion includesthree or more inductors twisted with each other and one of the three ormore inductors of the first portion is connected in series to a firstcapacitor.
 11. The mutually induced filter of claim 10, wherein thesecond portion includes a plurality of inductors, wherein the inductorsof the second portion are coextensively twisted with the or moreinductors of the first portion to define one unitary wound body.
 12. Themutually induced filter of claim 10, wherein the second portion includesa plurality of inductors, wherein the inductors of the second portionand the three or more inductors of the first portion are twisted witheach other to facilitate a coupling of a second resonant frequencyassociated with the second portion to the first portion.
 13. Themutually induced filter of claim 10, wherein the second portion includesthree or more inductors twisted with each other and one of the three ormore inductors of the second portion is connected to a second capacitor,wherein the three or more inductors of the second portion are twistedwith the three or more inductors of the first portion to achieve themutual coupling between the first and second portions to further achievethe coupling of the first resonant frequency.
 14. The mutually inducedfilter of claim 13, wherein a combination of the first capacitor of thefirst portion and the one of the three or more inductors of the firstportion has the first resonant frequency and a combination of the secondcapacitor of the second portion and the one of the three or moreinductors of the second portion has a second resonant frequency, whereinboth the first and second resonant frequencies are the same, wherein themutual coupling between the first and second portions facilitates acoupling of the second resonant frequency from the second portion to thefirst portion.
 15. The mutually induced filter of claim 13, wherein acombination of the first capacitor of the first portion and the one ofthe three or more inductors of the first portion has the first resonantfrequency and a combination of the second capacitor of the secondportion and the one of the three or more inductors of the second portionhas a second resonant frequency, wherein both the first and secondresonant frequencies are different from each other, wherein the mutualcoupling between the first and second portions facilitates a coupling ofthe second resonant frequency from the second portion to the firstportion.
 16. A mutually induced filter for filtering radio frequency(RF) power from signals associated with a plurality of loads,comprising: a first portion connected to a first load element of a firstone of the loads for filtering RF power from one of the signals suppliedto the first load element, wherein the first load is associated with apedestal of a plasma chamber; a second portion connected to a secondload element of the first load for filtering RF power from another oneof the signals supplied to the second load element, a third portionconnected to a first load element of a second one of the loads forfiltering RF power from one of the signals received from the first loadelement of the second load, wherein the second load is associated withthe pedestal of the plasma chamber; and a fourth portion connected to asecond load element of the second load for filtering RF power fromanother one of the signals received from the second load element of thesecond load, wherein the first, second, third and fourth portions aretwisted and wound with each other to be mutually coupled with each otherto further facilitate a coupling of a resonant frequency associated withthe first portion to the second, third, and fourth portions, wherein thefirst portion includes three or more inductors twisted with each otherand one of the three or more inductors of the first portion is connectedin series to a first capacitor without being connected to a powersupply, wherein remaining two of the three or more inductors of thefirst portion are coupled to the power supply.
 17. The mutually inducedfilter of claim 16, wherein the second, third, and fourth portionsinclude a plurality of inductors, and the inductors of the second,third, and fourth portions are coextensively twisted with the three ormore inductors of the first portion to define one unitary wound body.18. The mutually induced filter of claim 16, wherein the second portionincludes three or more inductors twisted with each other, wherein thethird portion includes three or more inductors twisted with each other,wherein the fourth portion includes three or more inductors twisted witheach other and one of the three or more inductors of the second portionis connected to a second capacitor.